I never thought about it until a few hours ago. It just popped in there. They call the capital ships Star Destroyers, but all they can really do is "glass" a planet. And by glass I mean use laser cannons to decimate the surface. And in Halo they called it glassing a planet. Which sounds more menacing to me. lol And supposedly crashing a Star Destroyer into a planet just right will destroy the planet. That's from the novels and I'm sure a reason why the Force Awakens has a crashed SD in a Tatooine clone desert. lol In the Jedi Academy Trilogy, Admiral Dalaa, I think the only female Admiral in the Empire(Emperor is racist and sexist), attempts to destroy a planet like that. It probably wouldn't work in RL, but it's an interesting "pirate" thing to do. Ram 'em! lol
And the Death Star is a planet killing machine. I'm pretty sure it doesn't have a beam that's strong enough to overcome a star. The DS beam is really drilling a planet and popping it, and releasing its inner marshmallow. lol You can see I know the science well. lol
But still, the only "super weapon"(I'm sure that title's a reference to wunderwaffe) that killed a star was the Sun Crusher. The Eclipse Super Star Destroyer has a super laser, but I think it only kills planets. There could be others. I haven't read but 40% of the old EU. And only a few of the newer stuff BDBI(before Disney bought it).
I wonder what Disney has called the "super weapon" in TFA? The Annihilator! lol Or something else as basic. :)